Eyepiece units of this type are known in the art in various embodiments. To adjust the eyepiece in the longitudinal direction of the optical system in the eyepiece frame, on the one hand, and on the other hand to adjust the eyepiece frame, with the eyepiece installed, in the coupling element in the image plane, it is a common practice in the art to secure the components that are to be fixed in each case in the adjusted position by means of screws. This type of adjustment has thoroughly proved itself; yet there is a danger that very fine shavings or similar disruptive particles can separate from the threads that press inward and find their way into the eyepiece unit. In addition, adjustment is very complex and time-consuming.
Consequently it is the object of the invention to create an eyepiece for endoscopes which allows a simple and rapid adjustment.
According to a first embodiment of the invention, in which the eyepiece is mounted in the eyepiece frame so that it can be axially slid and can be secured in an individually adjustable adjustment position in the eyepiece frame, the object of the invention is fulfilled in such a way that the eyepiece can be fixed in the eyepiece frame without screws.
Thanks to the invention's avoidance of screws for fixing the eyepiece in the adjusted position in the eyepiece frame, there is no longer any danger that shavings or similar foreign bodies can enter the eyepiece unit during adjustment.
It is proposed according to the invention that, to secure the screwless fixing, the eyepiece can be fixed in the eyepiece frame by means of a clamping or friction lock. Through clean flat clamping of the components to one another, the two-sided friction forces are so clearly increased that, even without the use of a screw, the component to be fixed can be secured in the adjustment position.
According to a first practical embodiment of the invention, to produce the clamping and/or friction lock it is proposed that in the interior of the eyepiece frame configured as an essentially cylindrical sleeve, at least one clamping element is positioned which reduces the inner diameter of the eyepiece frame, and that this unit, fully installed, interacts with the eyepiece installed in the eyepiece frame, in such a way that at least one clamping element is advantageously configured as an O-ring.
According to a second practical embodiment of the invention, it is proposed that to produce the clamping and/or friction lock the eyepiece frame is configured as an essentially cylindrical clamping sleeve, which when installed clamps and surrounds the inserted eyepiece in such a way that the outer diameter of the eyepiece is slightly larger than the inner diameter of the clamping sleeve. Because of the difference in diameter, the eyepiece frame configured as a clamping sleeve is widened by the insertion of the eyepiece and the eyepiece is clamped and held secure.
To configure the eyepiece frame as a clamping sleeve, this sleeve has according to the invention at least one and preferably three expansion slits running in the axial direction of the eyepiece frame. These expansion slits allow the larger-diameter eyepiece to be inserted into the eyepiece frame.
It is further proposed with the invention that alternatively to fixing the eyepiece by means of clamping and/or friction locks in the eyepiece frame, the fixing can be achieved by magnetic force. Fixing by magnetic force has the advantage of further reducing the danger of material abrasion occurring in the mutual fixing of the components.
In order to be able to adjust the eyepiece frame with the eyepiece mounted in the coupling element in the image plane, it is proposed with the invention that the eyepiece frame is positioned in the coupling element so that it can slide perpendicularly to the longitudinal axis and that it can be fixed in an individually adjustable adjustment position in the coupling element. This adjustment position in the coupling element, according to the invention, is also preferably able to be fixed by means of clamping and/or friction lock or even screwlessly.
The actual connecting of the eyepiece frame with the coupling element is achieved, according to a preferred embodiment of the invention, by a stop mechanism whose parts, both on the eyepiece frame side and on the coupling element side, interact to form a releasable but secure connection.
According to a first practical embodiment of the invention it is proposed that the stop mechanism is configured as a bayonet connection. The configuration as a bayonet connection constitutes a means of connecting that functions simply and quickly, one whose configuration requires no finely cut threads as are found with classic screw-in connections.
According to a second practical embodiment of the invention, it is further proposed that the stopping mechanism is configured on one of the components that are to be connected, as a notching or screw-in sleeve that can be secured on the other respective component. This screw-in sleeve can, for instance, take the form of a screwed cap, which is screwed onto an outer thread on another component. Because both the thread of the screwed cap and the opposite thread for securing the screwed cap are positioned on the outside of the eyepiece unit, there is no danger here that shreddings caused by abrasion can make their way inside the eyepiece unit.
Producing the clamping and/or friction lock required for fixing the eyepiece frame in the adjustment position occurs, according to the invention, by means of at least one pressure element mounted in the coupling element, by means of which the end surfaces of the eyepiece frame and of the coupling element that are coupled together by the stop mechanism can be pressed against one another.
It is proposed with a first practical embodiment of the invention that the pressure element takes the form of an O-ring mounted in the coupling element.
According to an alternative embodiment of the invention, the pressure element takes the form of a spring element mounted in the coupling element, which spring element can advantageously serve, in addition, as a length adjustment when the endoscope is under thermal and/or mechanical pressure.
It is further proposed with the invention that alternatively to fixing the eyepiece frame by means of clamping and/or friction lock in the coupling element, the fixing can occur by magnetic force. The fixing by magnetic force has the advantage of reducing the risk of material abrasion occurring in mutual fixing of the components.